Cleaning method of treatment equipment and treatment equipment

ABSTRACT

In a state of the inside of a treatment chamber of treatment equipment being evacuated, therein a cleaning gas containing trifluoroacetic acid (TFA) as a cleaning agent is supplied. Metal such as copper used in the formation of an interconnection or an electrode and stuck on an inner wall surface of the treatment chamber, when coming into contact with the cleaning agent (TFA) in the cleaning gas, without forming an oxide or a metallic salt, is directly complexed. The complex is sublimed due to the evacuation and is exhausted outside the treatment chamber. Accordingly, at less labor and low cost, the cleaning can be efficiently implemented.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning method of cleaningequipment, in particular to a cleaning method for removing metal or thelike stuck to an inner wall of a treatment chamber of the treatmentequipment and treatment equipment enabling such cleaning.

2. Description of the Related Art

When depositing, by the use of treatment equipment such as ChemicalVapor Deposition (CVD) equipment or the like, a thin metal film on a Siwafer (hereafter refer to as “wafer”), after accommodating the wafer inthe treatment chamber, a treatment gas is supplied. The treatment gascontains various kinds of metals such as copper, the metal segregatingin thin film on the wafer.

When the treatment gas sticks on an inner wall of the treatment chamber,also on the inner wall surface of the treatment chamber, a thin metalfilm is formed. The thin film stuck on the inner wall surface of thetreatment chamber, when being left as it is, may cause problems whentreating the wafer. Accordingly, it is necessary to implement periodicalcleaning of the treatment chamber to remove the thin metal film stuck onthe inner wall surface.

When the thin metal film is composed of metal difficult to ionize suchas copper or the like, it can be removed with difficulty. Accordingly,in the treatment chamber to which the thin metal film such as copper orthe like sticks, an oxidizing agent is supplied to oxidize copper tocopper oxide. Thereafter, the copper oxide is removed to clean theinside of the treatment chamber.

For instance, in Japanese Patent Publication No. JP-A-11-140652, thefollowing cleaning method of treatment equipment is disclosed:

-   (1) First, metal stuck on a treatment chamber wall is oxidized to    form metal oxide.-   (2) Then, the oxide is transformed to a metal complex.-   (3) Thereafter, the inside of the treatment chamber is evacuated to    sublime the metal complex.

Thus by implementing the processes of oxidizing, complexing andsubliming, the thin metal film stuck on the inner wall surface of thetreatment chamber is removed.

In the method, however, three steps are required to increase a totalnumber of steps, resulting in problems.

In addition, in the above method, β-diketone is employed in thecomplexing step. The β-diketone, being expensive, pushes up materialcosts in cleaning.

In addition, in the above method, since the step of oxidizing isincluded, oxygen may remain in the treatment chamber. Accordingly, dueto the remaining oxygen, the treatment chamber may be caused todeteriorate or the wafer may be adversely affected.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a cleaning methodcapable of efficiently cleaning treatment equipment with a small numberof steps and treatment equipment furnished with a cleaning mechanismcapable of implementing such cleaning.

Furthermore, another object of the present invention is to provide acleaning method capable of efficiently cleaning treatment equipmentwithout employing expensive cleaning material and at low cost andtreatment equipment provided with a cleaning mechanism capable ofimplementing such cleaning.

Furthermore, still another object of the present invention is to providea cleaning method in which treatment capability of treatment equipmentdoes not deteriorate after the treatment or quality of a treated waferdoes not fluctuate and treatment equipment furnished with a cleaningmechanism capable of implementing such cleaning.

(1) In order to accomplish the above object, a cleaning method of thepresent invention comprises a step off while supplying a cleaning gas ina treatment chamber of treatment equipment that treat a substrate,exhausting the cleaning gas from the treatment chamber. Here, thecleaning gas including a substance that directly complexes a prescribedmetal.

According to the present invention, the cleaning step is implemented bythe use of a cleaning gas including a substance that directly complexesmetal forming electrode or interconnection. As a result, upon supply ofthe cleaning gas in the treatment chamber, metal stuck on the inner wallsurface of the chamber is shortly complexed. The complexed metal isremoved, due to evacuation, from the treatment chamber together with thecleaning gas. Accordingly, the number of steps when cleaning is smalland cleaning can be shortly implemented without complexity.

In addition, there is no step of oxidizing metal stuck on the insidewall of the treatment chamber. Accordingly, there is no possibility forthe remaining oxygen to be adversely affected.

“The prescribed metal” means metal to use in the formation of electrodeor interconnection of a semiconductor device, for instance copper,aluminum, gold, silver or the like being cited. The above cleaningmethod is particularly effective in removing metal difficult to ionizesuch as copper.

Furthermore, “substance that directly complexes metal” means a substancethat, without requiring a particular additional step of forming metaloxide or metallic salt by the use of an oxidizing gas or the like,directly reacts with the metal to form a complex. As the example of the“substance that directly complexes metal”, carboxylic acid andcarboxylic acid derivatives can be cited.

Specifically, substances expressed by for instance RCOOH, RCOOR′, orR(COOH)_(n) (R and R′ denote hydrocarbon group that may contain halogenatom, n being an integer number) can be cited, more specificallytrifluoroacetic acid (TFA) being preferable.

By the use of less expensive material such as organic carboxylic acid orthe like such as TFA as a cleaning agent, the material cost in cleaningis not pushed up, resulting in less expensive cleaning.

As examples of “treatment equipment”, film forming equipment such asChemical Vapor Deposition (CVD) equipment, Physical Vapor Deposition(PVD) equipment, and plating equipment, or etching equipment, ChemicalMechanical Polishing (CMP) equipment can be cited.

An additive for promoting the complexing of the prescribed metal may becontained in the above cleaning gas.

Due to the addition of the additive, the complexing reaction is promotedto shorten the time for cleaning. As the additive, water vapor can beused for instance.

(2) Another cleaning method of the present invention comprises the stepsof supplying a cleaning gas and of exhausting the cleaning gas. In thestep of supplying a cleaning gas, a cleaning gas containing a substancethat directly complexes prescribed metal is supplied into a treatmentchamber of treatment equipment for treating a substrate. In the step ofexhausting the cleaning gas, the cleaning gas is exhausted from thetreatment chamber.

There is not a step of oxidizing the metal stuck onto the inner wallsurface of the treatment chamber. Accordingly, cleaning can be shortlycarried out without difficulty. There is not a possibility thatremaining oxygen adversely affects. Furthermore, the complexing andexhausting each are completely done, resulting in efficient cleaning.

In the above method, the supplying step and the exhausting step may bealternately repeated. Thereby, the treatment chamber can be assuredlycleaned.

(3) Treatment equipment of the present invention comprises a treatmentchamber, a susceptor, a treatment gas supply system, an evacuatingsystem and a TFA supply system. In the treatment chamber, a substrate istreated. The susceptor is disposed in the treatment chamber, on thesusceptor the substrate being disposed. The treatment gas supply systemsupplies a treatment gas containing copper as a component in thetreatment chamber. The evacuating system evacuates the inside of thetreatment chamber. The TFA supply system supplies trifluoroacetic acidin the treatment chamber.

The treatment equipment of the present invention, being furnished withthe TFA supply system in the treatment chamber to supply trifluoroaceticacid (TFA), can implement cleaning by a small number of steps, at lowcost and without damaging the treatment equipment.

In the aforementioned treatment equipment, as the treatment gas supplysystem, for instance one that comprises a treatment agent tank,treatment gas supply piping connecting the treatment chamber and thetreatment agent tank, and a treatment agent vaporizer disposed in themiddle of the treatment gas supply piping can be cited.

Furthermore, as the TFA supply system, for instance one that comprises aTFA tank and TFA supply piping connecting the TFA tank and the treatmentgas supply piping downstream the treatment agent vaporizer in adirection of a gas movement can be cited. As a result, metal stuck on aninner wall of the treatment gas supply piping can be cleaned.

In addition, in the above treatment equipment, it is preferable todispose a heater at least in a portion downstream the vaporizer of thetreatment agent supply piping. By heating the piping by means of theheater, the inside of the piping can be more efficiently cleaned.

For instance, in the treatment chamber, a heater for heating the innerwall of the treatment chamber, for instance a heater capable ofelectrically heating such as Nichrome wire or the like may be built in.

As the treatment agent tank, a tank containing a treatment agentessentially consisting of copper can be cited.

The treatment equipment may comprise a supply system for supplying anadditive that promotes the completing of copper. By the addition of theadditive, the complexing can be promoted to result in shortening of thecleaning time. The supply system can be constituted of for instancepiping connected to any one of the treatment chamber, the treatment gassupply piping and the TFA supply piping.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical section showing an entire configuration oftreatment equipment (CVD equipment) involving the present invention.

FIG. 2 is a diagram schematically showing a piping route of treatmentequipment involving the present invention.

FIG. 3 is a flowchart of a cleaning method involving a firstimplementation mode.

FIG. 4 is a flowchart of a cleaning method involving a secondimplementation mode.

FIG. 5 is a flowchart of a cleaning method involving a thirdimplementation mode.

FIG. 6 is one graph showing results of cleaning due to a secondembodiment.

FIG. 7 is another graph showing results of cleaning due to a secondembodiment.

FIG. 8 is a graph showing results of cleaning due to a third embodiment.

DESCRIPTION OF PREFERRED EMBODIMENT

(1st Mode of Implementation)

In the following, a cleaning method and treatment equipment involving afirst implementation mode of the present invention will be explained.

FIG. 1 is a vertical section showing an entire configuration of CVDequipment furnished with a cleaning mechanism involving the presentinvention.

As shown in FIG. 1, the treatment equipment 10 comprises a treatmentchamber 1 formed in approximate cylinder from for instance Al or thelike.

On a ceiling of the treatment chamber 1, a showerhead 13 is disposed tosupply a treatment gas therein. The showerhead 13 comprises a diffusionchamber 13 a having a base plate where a plurality of orifices 13 b, 13b and so on are bored. The treatment gas supplied through a treatmentgas supply piping 14 to the showerhead 13, after diffused once in thediffusion chamber 13 a, is discharged from the orifices 13 b, 13 b andso on to a wafer W disposed on a susceptor 2.

On a sidewall surface in the neighborhood of the ceiling of thetreatment chamber 1, piping 29A and 29B are disposed for nitrogen andwater vapor, respectively. The piping 29A supplies a nitrogen gas toreplace an atmosphere in the treatment chamber when for instance thewafer W is transferred in and out of the treatment chamber 1. The piping29B, as mentioned below, supplies an additive such as water vapor thatpromotes a complexing reaction in the treatment chamber 1.

Inside the treatment chamber 1, the susceptor 2 for disposing the waferW as a substrate to be treated is supported by a base through a prop 3.As material of the susceptor 2, for instance graphite, amorphous carbon,composite carbon, and AlN can be used. Downward the susceptor 2, alifter pin 4 made of quartz glass is disposed movable up and down by notshown elevating means. The lifter pin 4 penetrates a through hole 4Adisposed in the susceptor 2 to hold up the wafer W when transferring inand out.

Inside the susceptor 2, a powerful heater 5 consisting of Nichrome wireor the like is disposed. By means of the heater 5, the susceptor 2 inthe treatment chamber 1 is heated, thereby indirectly heating the waferW at a temperature in the range of for instance from approximate 150 to300° C. to maintain there.

On the sidewall of the treatment chamber 1, a gate valve 11 is disposedto open when transferring the wafer W in and out of the treatmentchamber 1. At a periphery of a base of the treatment chamber 1, anexhaust 12 connected to a vacuum pump not shown in the figure isdisposed to evacuate the treatment chamber 1.

FIG. 2 is a diagram schematically showing piping route of the treatmentequipment involving present implementation mode.

As shown in FIG. 2, to the piping 14A upstream the treatment gas supplypiping 14 connected to the showerhead 13 in the treatment chamber 1, atreatment agent tank 17 is connected to receive the treatment agent.

At an upper portion of the treatment agent tank 17, inert gas supplypiping 18 for supplying an inert gas such as Ar or the like is disposedtogether with an opening valve 19. Through the piping 18, an inert gassuch as Ar or the like is supplied into the treatment agent tank 17. Aliquid surface of the treatment agent is pushed down by the suppliedinert gas, thereby the treatment agent in the treatment agent tank 17being supplied into the piping 14.

In the treatment agent tank 17, a treatment agent for forming a thinfilm of the metal used for the formation of an interconnection or anelectrode of a semiconductor element, for instance copper, isaccommodated. For instance, precursors containing copper, in moredetail, the following substances can be cited.

The treatment agent contains Cu⁺¹ (hexafluoroacetylacetonate) and silylolefin ligand.

The silylolefin ligand is contained in a substance selected from a groupconsisting of trimethylvinylsilane (TMVS), dimethoxymethylvinylsilane(DMOMVS), methoxydimethylvinylsilane (MODMVS), trimethoxyvinylsilane(TMOVS), triethoxyvinylsilane (TEOVS), ethoxymethoxymethylvinylsilane(EOMOMVS), diethoxymethylvinylsilane (DEOMVS),diethoxymethoxyvinylsilane (DEOMOVS), ethoxydimethoxyvinylsilane(EODMOVS), ethoxydiethylvinylsilane (EODEVS), diethoxyethylvinylsilane(DEOEVS), dimethoxyethylvinylsilane (DMOEVS), ethoxydimethylvinylsilane(EODMVS), methoxydiethylvinylsilane (MODEVS) andethylmethoxymethylvinylsilane (EMOMVS).

In the middle of the piping 14, a liquid massflow controller 15B isdisposed, thereby a flow rate of the treatment agent pumped out of thetreatment agent tank 17 being controlled. Upstream the massflowcontroller 15B in a direction of movement of the treatment agent, anopening valve 15C is disposed, downstream the massflow controller 15B ina direction of movement of the treatment agent an opening valve 15Cbeing disposed.

In the middle of the piping 14B connecting the massflow controller 15Band the opening valve 15C, a branch line 14C is connected to function asa drain, an opening valve 15D being disposed thereto. Further downstreamthe opening valve 15C, a vaporizer 16 is disposed to vaporize thetreatment agent there. The piping 14D further downstream the vaporizer16 is connected through the opening valve 16C to the showerhead 13. Inthe middle of the piping 14D, a branch line 14E is connected to functionas a drain, an opening valve 16E being disposed there.

To the vaporizer 16, another cleaning piping 20 is disposedindependently from the piping 14. As shown in FIG. 2, to piping 20Aupstream the cleaning piping 20 connected to the vaporizer 16, acleaning agent tank 21 is connected to accommodate the cleaning agentsuch as for instance trifluoroacetic acid (TFA).

At an upper portion of the cleaning agent tank 21, inert gas supplypiping 22 for supplying an inert gas such as Ar or the like is disposedtogether with an opening valve 23. Through the piping 22, the inert gassuch as Ar or the like is supplied in the cleaning agent tank 21.Thereby, a liquid surface of the cleaning agent is pushed down to supplythe cleaning agent in the cleaning agent tank 21 into the piping 20. Inthe middle of the piping 20, a liquid massflow controller 25 isdisposed, a flow rate of the cleaning agent pumped out of the cleaningagent tank 21 being controlled. Upstream the massflow controller 25 in adirection of movement of the cleaning agent, an opening valve 24 isdisposed. In addition, downstream the massflow controller 25 in adirection of movement of the cleaning agent, an opening valve 2.7 isdisposed.

In the middle of the piping 20B connecting the massflow controller 25and the opening valve 27, a branch line 20C is connected to function asa drain, an opening valve 26 being disposed to the branch line 20C.Further downstream the opening valve 27, a branch line 20D is disposed,thereto. 20D an opening valve 28 being disposed.

To the vaporizer 16 and the piping 14 downstream the vaporizer 16, aheater 30 such as a ribbon heater is disposed, heating the vaporizer 16and the piping 14 downstream the vaporizer 16 to a prescribedtemperature.

Next, a procedure when cleaning the treatment equipment by the use ofthe cleaning method of the present invention will be explained. FIG. 3is a flowchart showing a flow when the cleaning method of the presentinvention is implemented.

When cleaning the treatment equipment, first, valves such as openingvalves 19, 15A and 15C are closed to stop supplying the treatment agent(step S11).

Then, the heater 30 is turned on to heat the vaporizer 16 and the piping14 and the treatment chamber 1 downstream the vaporizer 16 up to forinstance 300° C. (step S12)

Next, the opening valves 23, 24, 27 and 16C are opened and the massflowcontroller 25 is turned on to start supplying the cleaning agent (stepS13).

When the cleaning agent is supplied from the cleaning agent tank 21through the piping 20, the cleaning agent is vaporized due to theoperation and heat of the vaporizer 16.

The vaporized cleaning agent comes into contact with the inner walls ofthe vaporizer 16 and the piping 14 and further with metal such as copperstuck on the inner wall of the treatment chamber 1. The insides of thevaporizer 16, the piping 14 and the treatment chamber 1 are heated tosufficiently high temperatures. Accordingly, the moment when thesupplied cleaning agent and the metal come into contact, a complex israpidly formed. The metal is, in the treatment equipment, material forforming the electrode and the interconnection of a semiconductorelement.

The inside of the treatment chamber 1 is evacuated and maintained at areduced pressure. Accordingly, the metal complex formed as in the aboveis sublimed and exhausted outside the treatment chamber 1.

As explained above, according to the cleaning method involving thepresent implementation mode, the treatment equipment is cleansed by theuse of the cleaning gas containing a substance that directly complexesthe metal that forms the electrode or the interconnection. Accordingly,the cleaning can be simply and shortly carried out with less labor.

In addition, due to the use of less expensive substances such astrifluoroacetic acid (TFA) as used in the above implementation mode,material cost necessary for cleaning can be reduced.

Furthermore, by the use of the treatment equipment furnished with amechanism supplying the cleaning agent to the vaporizer of the treatmentgas supply piping as shown in the above implementation mode, the metalsuch as copper stuck not only to the treatment chamber but also to theinside of the treatment gas supply piping can be cleaned with ease.

(2nd Implementation Mode)

In the following, a second implementation mode of the present inventionwill be explained. In the following implementation modes, contentsduplicating with the preceding implementation mode will be omitted fromexplanation.

The present implementation mode is configured in two steps of complexingmetal stuck to the inside of the treatment chamber 1 and of sublimingthe generated complex due to evacuation to remove.

FIG. 4 is a flowchart showing treatment steps of the cleaning methodinvolving the present implementation mode.

When implementing the cleaning method involving the presentimplementation mode, first, as shown in the flowchart of FIG. 3, in thetreatment equipment shown in FIG. 2, the valves such as opening valves19, 15A and 15C are closed to stop the supply of the treatment agent(step S21).

Next, the heater 30 is turned on to heat the vaporizer 16 and the piping14 and the treatment chamber 1 downstream the vaporizer 16 up to aprescribed temperature, for instance 300° C. (step S22).

Then, the opening valves 23, 24, 27 and 16C are opened and the massflowcontroller 25 is turned on to start the supply of the cleaning agent(step S23).

Upon supplying the cleaning agent from the cleaning agent tank 21through the piping 20, the cleaning agent is vaporized due to operationand heat of the vaporizer 16. The vaporized cleaning agent comes intocontact with the inner walls of the vaporizer 16 and the piping 14 andfurther with metal stuck on the inner wall of the treatment chamber 1.The metal is one such as copper or the like that is used to form theelectrode and the interconnection of a semiconductor element. At thattime, the insides of the vaporizer 16, the piping 14 and the treatmentchamber 1 are heated sufficiently high temperatures. Accordingly, themoment when the supplied cleaning agent and the metal come into contact,a complex is rapidly formed.

After the course of a prescribed time period to sufficiently complex themetal, the opening valves 23, 24 and 27 are closed to stop the supply ofthe cleaning agent.

Approximately simultaneously with the stoppage of the supply of thecleaning agent, a vacuum pump is operated to evacuate the inside of thetreatment chamber 1 (step S24).

By evacuating the treatment chamber 1, the metal complex generated inthe step S23 is sublimed to exhaust outside the treatment chamber 1.

As explained above, the cleaning method involving the presentimplementation mode is configured in two separate steps of complexingthe metal and subliming the complex generated in the complexing step. Asa result, the steps of complexing and subliming can be completelyimplemented, respectively, resulting in a peculiar effect of improvingcleaning efficiency.

(3rd Implementation Mode)

In the following, a third implementation mode of the present inventionwill be explained.

The present implementation mode is configured so that the step ofcomplexing the metal stuck to the treatment chamber and the step ofsubliming the generated complex due to the evacuation to remove areintermittently repeated.

FIG. 5 is a flowchart of a cleaning method involving the presentimplementation mode.

When implementing the cleaning method involving the presentimplementation mode, similarly with the second implementation mode,after the stoppage of supply of the treatment agent (step S31) andheating of the vaporizer, the piping and the treatment chamber (stepS32), the cleaning agent is started supplying (step S33).

After the course of a prescribed time to sufficiently complex a surfaceof the metal stuck on the inner wall of the treatment chamber 1, thecleaning agent'is stopped supplying (step S34). Then, the evacuation ofthe treatment chamber is began (step S35).

After the course of a prescribed time to sufficiently sublime the metalcomplex formed in the step S33 to evacuate outside the treatmentchamber, the evacuation is stopped (step S36).

Next, an amount of the metal stuck on the inner wall surface of thetreatment chamber 1 is confirmed (step S37). The confirmation operationmay be implemented by directly observing a sticking state of metal onthe inner wall of the treatment chamber or may be implemented byconfirming a remaining amount of a metal film formed on a surface of amonitoring wafer W.

When, in the step S37, the amount of metal stuck on the inner wallsurface of the treatment chamber 1 is confirmed to be sufficientlyreduced, the cleaning is stopped.

On the contrary, when, in the step S37, the amount of metal stuck on theinner wall surface of the treatment chamber 1 is not confirmed to besufficiently reduced, the operation of the steps from S33 to S37 arerepeated. Thus, up to the complete removal of the stuck metal, theoperation of cleaning is repeated.

As explained above, according to the cleaning method involving thepresent implementation mode, the steps of complexing the metal and ofsublimating the complex formed through the complexing step are separatedin two stages and intermittently repeated. Accordingly, the complexingand the sublimation can be completely implemented, resulting in aneffect of improving cleaning efficiency.

(4th Implementation Mode)

In the following, a fourth implementation mode of the present inventionwill be described.

In the present implementation mode, in the step of complexing the metalstuck on the inner wall of the treatment chamber 1, an additive is addedin the cleaning gas to promote the complexing of the metal. As specificsteps, the treatment steps of FIGS. 3 to 5 explained in the firstthrough third implementation modes can be applied. That is, in any oneof the steps of S13 of FIG. 3, S23 of FIG. 4 and S33 of FIG. 5, togetherwith the supply of the cleaning agent, the additive is only necessary tobe added. As the additive for promoting the complexing, water vapor oroxygen can be used.

For instance, in the step S13 of FIG. 3, the cleaning agent (cleaninggas) vaporized in the vaporizer 16 is assumed to be supplied in thetreatment chamber 1. Together with the supply of the cleaning gas intothe treatment chamber 1, from the piping 29B water vapor is suppliedinto the treatment chamber 1.

As a result, the water vapor is added to the cleaning gas. The cleaninggas comes into contact with the metal such as copper stuck on the innerwall of the treatment chamber 1 to form complex. The water vapor that isadded to the cleaning gas promotes the formation of the complex. Thecomplexing of the metal is over in a short time, resultantly.

The addition of water vapor or the like to the cleaning gas is notnecessarily implemented through the piping separate from the piping 14that supplies the cleaning gas, but can be implemented by adding watervapor in the middle of the piping 14.

(Embodiment 1)

In the following, embodiments of the present invention will beexplained.

With the treatment equipment explained in the aforementionedimplementation modes, a wafer W on which surface copper of a thicknessof 5000 angstrom is deposited is disposed on the susceptor 2.Thereafter, an atmosphere in the treatment chamber 1 is replaced by purenitrogen. The susceptor 2 is heated to 300° C., followed by, through thesupply piping 14, supplying a gas mixture of 35 sccm of TFA diluted bynitrogen. At that time, the pressure in the treatment chamber 1 iscontrolled to be 1.33×1⁴ Pa (100 Torr). After the state of constant gaspressure is maintained for 10 min, the gas mixture of TFA and nitrogenis ceased to supply.

Thereafter, gas remaining in the treatment chamber 1 is evacuated,followed by taking out the wafer W.

From observations of the wafer W by means of a scanning electronmicroscope, it is confirmed that the copper on the wafer W is completelyremoved by means of the dry cleaning due to TFA.

(Embodiment 2)

With samples of the wafer W thereon copper is deposited similarly withEmbodiment 1, the temperature (wafer temperature) of the susceptor 2 andthe gas pressure in the treatment chamber 1 are varied to investigate anamount of etching of copper.

As the sample, a wafer W thereon copper is deposited is cut into squaresof 2×2 mm to use. Furthermore, as the cleaning gas, a gas mixture offlow rate 3.7 sccm of TFA and flow rate 40 sccm of nitrogen is used. Aconstant gas pressure is maintained for 10 min to implement thecomplexing. After the stoppage of the gas supply, the evacuation iscarried out to sublime the complex. Thereafter, the sample is taken outof the treatment chamber 1. The sample is compared with that before thecleaning in weight to obtain the amount of etched copper.

FIG. 6 is a graph showing etched amount when, with a gas pressure in thetreatment chamber 1 fixed at 100 Torr, the temperature of the susceptor2 is varied from 150° C. to 300° C. FIG. 7 is a graph showing an etchedamount when, with the temperature of the susceptor 2 fixed at 300° C.,the gas pressure in the treatment chamber 1 is varied from 10 Torr to100 Torr.

Abscissas of graphs of FIGS. 6 and 7 denote the temperature of thesusceptor 2 and the gas pressure in the treatment chamber 1,respectively. Ordinates of graphs of FIGS. 6 and 7 each denote etchedamount of copper expressed by the weight change (mg) before and afterthe cleaning.

From FIG. 6, as the temperature rises as 150, 200 and 300° C., theetched amount increases. From FIG. 7, as the gas pressure rises as 10,100 Torr, the etched amount increases.

The times necessary for complexing in FIGS. 6 and 7 are the same.Accordingly, the increase of the etched amount means an increase of thespeed of complexing, resultantly an increase of the speed of etching.

As mentioned above, due to the increase of the temperature and gaspressure, the speed of etching (speed of complexing) can be increased.

(Embodiment 3)

In the present embodiment 3, in the course of complexing, from thepiping 29B water vapor is supplied to measure a change of weights of theetched copper.

Samples to measure, gas to use and flow rate of the gas are the samewith Embodiment 2 (sample: wafer W of 2×2 mm thereon copper isdeposited, cleaning gas: gas mixture of flow rate 37 sccm of TFA andflow rate 40 sccm of nitrogen). The temperature of the susceptor 2 andthe gas pressure in the treatment chamber 1 are 300° C. and 100 Torr,respectively, that showed the maximum etched amount in Embodiment 2. Thetime for the step of complexing is 3 min.

FIG. 8 is a graph showing the etched amount of copper when water vaporis supplied in the treatment chamber 1 in the course of the complexingin comparison with the case where water vapor is not employed. Theetched amount of copper is expressed, similarly with embodiment 2, bythe weight change (mg) before and after the cleaning treatment. In thecase of water vapor being supplied, water vapor is supplied by 8.5 sccm(as gas).

From FIG. 8, by adding water vapor to the cleaning gas by approximately19 atomic %, the etched amount of copper is increased by 37%.

From the above, it is found that by the addition of the water vapor, theetching speed (complexing speed) can be improved.

(Other Implementation Mode)

The present invention is not restricted to the range set forth in theabove implementation modes. In the aforementioned implementation modes,the explanation is given with CVD equipment as an example. However, thepresent invention can be applied in treatment equipment other than theCVD equipment, for instance in PVD equipment or the like.

Furthermore, in the above implementation modes, in the middle of thepiping that supplies the treatment agent to the treatment chamber, thecleaning agent such as TFA or the like is supplied. The presentinvention also can be applied in the treatment equipment furnished withthe piping for directly supplying the cleaning agent in the treatmentchamber 1.

Furthermore, in the above implementation modes, the treatment equipmentof Si wafers is explained as an example. However, the present inventionalso can be applied in the treatment equipment for treating glasssubstrates for liquid crystal display (LCD).

1-10. (canceled)
 11. A treatment apparatus, comprising: a chamber; asusceptor mounting a substrate in the chamber; a first source supplyinga treatment agent containing a metal for forming a metal film on thesubstrate; a second source supplying a cleaning agent containing one ofa carboxylic acid and a derivative of a carboxylic acid for reacting ametal film on an inner wall of the chamber to form a metal complex ofthe metal and the cleaning agent; a vaporizer vaporizing the treatmentagent and the cleaning agent; a first pipe supplying the treatment agentfrom the first source to the vaporizer; a second pipe supplying thecleaning agent from the second source to the vaporizer; a third pipesupplying the vaporized treatment agent and the vaporized cleaning agentfrom the vaporizer to the chamber; a heater heating the chamber, thethird pipe, and the vaporizer; and a vacuum pump exhausting the chamber,wherein the metal film is formed on the inner wall of the chamber by thevaporized treatment agent and the metal film on the inner wall iscleaned by the vaporized cleaning agent. 12-16. (canceled)
 17. Thetreatment apparatus of claim 11, wherein the one of the carboxylic acidand the derivative comprises a compound selected from the groupcomprising RCOOH, RCOOR′, and R(COOH)_(n), R, R′ are hydrocarbon groupcontaining halogen atom, and n is an integer.
 18. The treatmentapparatus of claim 11, wherein the carboxylic acid comprisestrifluoroacetic acid.
 19. The treatment apparatus of claim 11, whereinthe metal is copper.
 20. The treatment apparatus of claim 11, furthercomprising a supply unit for supplying an additive to promote formationof the metal complex.
 21. The treatment apparatus of claim 20, whereinthe additive includes oxygen or water vapor.
 22. The treatment apparatusof claim 11, wherein the treatment agent contains CU⁺¹(hexafluoroacetylacetonate) and silyl olefin ligand.
 23. The treatmentapparatus of claim 11, wherein the heater heats the susceptor.
 24. Thetreatment apparatus of claim 11, further comprising a drain exhaustingthe third pipe.
 25. The treatment apparatus of claim 11, furthercomprising a shower head supplying the vaporized treatment agent and thevaporized treatment agent from the third pipe into the chamber.